A cobporation op pennsyl



Patented Feb. 26, 1929.

UNITED STATES PATENT OFFICE.

DAVID J'. GILES, OF LATROBE, PENNSYLVANIA, ASSIGNOR TO LATROBE ELECTRIC STEEL COMPANY, OF LATROBE, PENNSYLVANIA, A CORPORATION OF PENNSYL- VAN IA.

INGOT MOLD.

No Drawing.

The invention relates to molds for casting steel ingots.

It is well known that molten steel taken from a melting furnace is poured into molds for forming ingots which are'later rolled or otherwise worked or formed into desired shapes. Heretofore the prevailing practice, established as a result'of long cumulative experience, has been to make the ingot molds of cast iron containing no alloying constituents except those usually found in it as impurities or present as incidental to its 1nanufacture.

In the use of ingot molds molten steel poured into them tends to weld to their interior surfaces, and Where the molten steel strikes the sides of the molds during pouring operation furrows are cut into the mold walls, with the result that the walls of the molds are gradually eaten until they become so furrowed or roughened that ingots cast in them have projections which must be removed in order to roll seamless billets from them.

In practice an ingot mold which with stands these prejudicial actions of molten steel upon it to such an extent that it may be used for casting as many as seventy-live ingots is considered to be an unusually good mold, the average life of an ingot mold being about fifty-five heats.

T he object of this invention is to provide a mold for casting steel ingots which will have much greater durability than ingot molds heretofore used, and which will bev much susceptible to fur-rowing in service.

The invention is 1.)redicated upon my discovery that a mold for casting steel ingots when formed of cast iron containing an appreciable' anmunt of chromium is highly rcsistant to the hcatin g and furrowing action of molten steel. As a specific example of my discovery, ingot molds made of cast iron containing 3.67% carbon and 1.32% chromium have each been used for more than 180 eastings of steel and are still in very serviceable condition. Other molds made of cast iron containing 3.72% carbon and 89% chromium Serial N0. 153,040.

were used for an average of 110 castings of steel before they became materially affected by the action of the molten steel.

In general the chromium content of the cast iron maybe as low as and is preferably not higher than 3.00%. Within this range it is preferred to use a chromium content of from about .50 to 2.00%. The remainder of the cast iron need not contain any additional alloying constituents, although it will be understood that it may, and usually does, contain the usual constituents present as impurities and as incidental to the process of manufacture of the iron.

Ingot molds provided according to this invention may be of the well known or of any desired, shapes, forms, and sizes, and may be made as one or two part molds, both of which are now commonly used.

The term cast iron is used throughout the specification and in the claims in its tech nical sense as meaning iron containing from about 2 to 4 per cent carbon.

According to the provisions of the patent statutes I have explained the principle of my invention, and have described specific eX- amples of how it may be practiced. How ever, I desire to have it understood that, Within the scope of the appended claims, the in vention may be practiced otherwise than as specifically described.

I claim:

1. A mold for casting steel ingots, the mold being formed of a cast iron alloy containing from about .25 to 3.00% chromium, the remainder of the alloy being principally cast iron.

2. A mold for casting steel ingots, the mold being formed of a cast iron alloy containing from about .50 to 2.00% chromium, the re mainder of the alloy being principally cast iron.

3. A mold for casting steel ingots. the mold being formed of a ferrous alloy having cast iron as its base and containing chromium.

In testimony whereof, I sign my name.

DAVID J. GILES. 

